Vapor generator

ABSTRACT

A lightweight highly efficient vapor generator having low thermal inertia and fast response to varying load demands, particularly for automotive use. A series of radially spaced concentric heat sleeves surrounds the combustion chambers with incoming air passing between these sleeves for preheating the air used for combustion, this air providing heat insulation for the outer shell. An air register at one end of the shell imparts a swirling circular motion to the incoming air creating a vortex flow in the primary combustion chamber which continues on into secondary and tertiary combustion chambers. The wall of the tertiary combustion chamber is lined with vapor superheat tubes which receive vapor from banks of vapor generating tubes near mid length position in the shell, and these tubes in turn receive liquid from preheater tubes at the opposite end of the shell. The combustion gases pass between these tubes and exhaust from said opposite end of the shell. All radiant energy from the combustion chambers is intercepted and utilized with a minimum of loss to the outer shell.

United States Patent Richard J. Smith 8591 Pyle Way, Midway City, Calif.92655 [21] App1.No. 18,650

[22] Filed Mar. 11, 1970 [45] Patented Aug. 10, 1971 [72] Inventor [54]VAPOR GENERATOR 2,787,256 4/1957 [lune .1:

122/DIG. 1

Primary Examiner-Kenneth W. Sprague Attorney-Lee R. SchermerhornABSTRACT: A lightweight highly efficient vapor generator having lowthermal inertia and fast response to varying load demands, particularlyfor automotive use. A series of radially spaced concentric heat sleevessurrounds the combustion chambers with incoming air passing betweenthese sleeves for preheating the air used for combustion, this airproviding heat insulation for the outer shell. An air registerat one endof the shell imparts a swirling circular motion to the incoming aircreating a vortex flow in the primary combustion chamber which continueson into secondary and tertiary combustion chambers. The wall of thetertiary combustion chamber is lined with vapor superheat tubes whichreceive vapor from banks of vapor generating tubes near mid lengthposition in the shell, and these tubes in turn receive liquid frompreheater tubes at the opposite end of the shell. The combustion gasespass between these tubes and exhaust from said opposite end of theshell. All radiant energy from the combustion chambers is interceptedand utilized with a minimum of loss to the outer shell.

PATENTED AUG! 0 ran SHEET 2 OF 2 VAPOR GENERATOR BACKGROUND OFTHE-INVENTION This invention relates to a vapor generator and hasparticular reference to an oil fired vapor generator adapted forautomotive use.

Many attempts have been made to develop a practical and suitable steamgenerator for operating a steam engine to drive an automobile. Therequirements are vastly different, how ever, from those of conventionalsteam generators for other purposes and no vapor generator has yet beendeveloped which is competitive with internal combustion engines. Theconditions of road vibration, size, weight, quick startup, fast responseto widely varying load demands, safety and a multitude of other exactingrequirements peculiar to this field of use have thus far defeated allattempts to provide a truly successful vapor generator.

Objects of the present invention are, therefore, to provide a practicaland efficient vapor generator for an automobile engine, to provide arelatively compact, lightweight and inexpensive vapor generator withoutrefractory insulation, to provide a vapor generator having low thermalinertia and fast response to widely varying load demands, to" provide arelatively simple tube system for a vapor generator, and to provide avapor generator in which there is efficient and clean combustion of fuelwith a low level of harmful exhaust emissions to pollute the air.

SUMMARY OF THE INVENTION In the present construction heavy and bulkyconventional refractory insulation is obviated by utilizing the incomingair as an insulator for the outer shell or casing. This is accomplishedby a plurality of radially spaced concentric heat sleeves whichintercept radiation from the combustion cham bers and utilize such heatto preheat the incoming air for greater combustion efficiency.

A novel form of air register at one end of the casing imparts a circularswirling motion to the incoming air, distributing the air in concentriclayers within the combustion chambers so that the hottest air movesaround the outside wall of the primary combustion chamber and thecoolest air flows directly into the center of the secondary combustionchamber. This air register is also arranged to intercept radiant heat atone end of the casing and utilize this heat for further heating of theincoming air. A tangential burner nozzle adjacent the outer wall of theprimary combustion chamber initiates combustion in the hottest layer ofair, the flame moving inwardly toward the axis to enter the secondarycombustion chamber and mix with the cooler air.

The wall of the tertiary combustion chamber area is lined with superheattubes which intercept and utilize outwardly directed radiation.Radiation toward the opposite end of the casing is intercepted andutilized by banks of vapor generating tubes and liquid preheating tubes,around all of which tubes the flame and products of combustion must passto reach the exhaust opening at said opposite end of the casing.

The invention will be better understood and additional ob jects andadvantages will become apparent from the following description of thepreferred embodiment illustrated in the accompanying drawings. Variouschanges may be made, however, in the details of construction andarrangement of parts and certain features may be used without others.All such modifications within the scope of the appended claims areincluded in the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectionalview with parts in elevation, showing a vapor generator embodying theprinciples of the invention;

FIG. 2 is an enlarged view on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary perspective view showing the construction of theair register;

FIG. 4 is an enlarged fragmentary'view of a portion of FIG. 3; and

FIG. 5 is a view on the line 5-5 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The vapor generator is housed ina cylindrical outer shell or casing which contains therewithin aconcentric cylindrical inner shell 11. A space 12 between the two shellsprovides an annular passageway for incoming air as indicated by arrows13 in FIG. 1. The air is blown into the space 12 tangentially at thelower end of the casing by blower 15 in FIG. 5. Blower l5 dischargesinto a scroll casing 16 which communicates with an arcuate opening 17 inouter shell It) as shown in FIG. I. Thus, the air follows a spiral patharound shell 11 which is in clockwise direction in bottom plan view asindicated in FIG. 5 and counterclockwise in top plan view as indicatedin FIG. 2.

Shells l0 and 11 are secured to a bottom end wall 20 by screws 21 in apair of flange rings 22. These rings are spotwelded at 23 to end wall20. At intermediate height the concentric spacing of shell 11 withinshell 10 is maintained by a plurality of resilient curled tongues 24.These tongues are spotwelded to shell 10 arid merely bear against shell11 without any positive connection thereto. Tongues 24 are freelyyieldable to permit expansion and contraction of shell 11 as a result ofheating and cooling.

For convenience in assembly, the upper end of shell 10 is made as aseparate section, the joint between the two shells being indicated at25. Screws 26 secure the upper section to a ring 27 which is spotweldedto the lower section. For purposes of the present description, however,the two sections will be treated as a single continuous shell 10.

The spiral flow of incoming air 13 passes upward and enters threeannular passageways separated by a pair of heat sleeves 30 and 31 whichare maintained in concentric spaced relation, as shown, by additionalresilient curled tongues 24. Inner sleeve 30 has an inturned upper end32 and outer sleeve 31 has an inturned upper end 33 having a greaterradial extent than end 32. The spacing of these inturned ends ismaintained by additional resilient curled tongues 24. Outer shell 10 isconnected to a top end wall 35 by screws 21 in a flange ring 22 which isspotwelded to end wall 35 in the same manner as bottom end wall 20. Heatsleeves 30 and 31 thus form three concentric annular passages 36, 37 and38 for the incoming air 13. These heat sleeves surround a primarycombustion chamber A and the upper portion of a tertiary combustionchamber area C.

The three layers of air rising through passageways 36, 37 and 38 absorbheat from the combustion chambers and prevent outer shell 10 frombecoming hot to the touch. Inner shell 11 forms the wall of thecombustion chambers and radiates heat to sleeve 30, some of the heat inshell 11 and sleeve 30 being removed by air in passageway 36. Sleeve 30radiates heat to sleeve 31 and heat is removed from both of thesesleeves by air rising through passageways 37 and 38. Heat is alsoremoved from sleeve 31 by air in passageway 38. Thus, passageway 36conveys the hottest layer of air, passageway 37 conveys a layer of airat intermediate temperature, and passageway 38 conveys a layer ofrelatively cool air.

lnturned ends 32 and 33, being of different radial extent, conduct thelayers of air of different temperature to different regions under thetop end wall 35, the hottest air being discharged immediately insideshell 11, the air of intermediate temperature being conveyed betweeninturned ends 31 and 32 closer to the center of shell 11 and therelatively cool air from passageway 38 being directed by inturned end 33to a central region of the shell. The space receiving these three layersof air is designated as plenum chamber 39. The three layers of airentering the plenum chamber 39 are directed into the combustion chambersin circular swirling flow by an air register 40 having a series ofsector-shaped plates 41. Plates 41 are spotwelded together at theirapexes and are held in spaced relation to each other by rigid spacertongues 43 as shown in FIG. 3. Around the periphery of the register theplates are spaced apart by resilient, curled tongues 24. Air register 40is held against the upper edge of shell 11 by the resilient curledtongues 24 on the plates 41 and on the intumed ends 32 and 33 of theheat sleeves 30 and 31 as shown. Peripheral tabs 44 and welds 42 holdthe plate assemblage together as a unit.

Plates 41 are inclined in the manner of fan blades and have considerableoverlap to form sloping passages which enhance the circular swirlingmotion of the air passing downward through the air register. The overlapof plates 4! and inturned ends 32 and 33 intercepts upward radiationfrom the combustion chambers, producing radiation from one plate to thenext and heating the air between the plates as described in connectionwith the insulting and air heating action of heat sleeves 30 and 31.Thus, there is no direct radiation from the combustion chambers againstend wall 35 and the heat reaching end wall 35 by plate to plateradiation is largely removed by the relatively cool air from outerpassageway 38 which flows inwardly in contact with end wall 35 and thencontacts the center of the air register, cooling plates 41 and heatingthe air.

A depending circular skirt 50 is suspended from the under side of airregister 40 by means of tabs 52 welded to pl ites 41.

The lower edge of skirt 50 is spaced above an innular ly to skirt 50 andinturned end 33 overhangs skirt 50.

As shown in FlG. 2, fuel nozzle 60 injects a fine spray of oiltangentially into primary combustion chamber A directly into the vortexring of the hottest iayer of air from passageway 36 which flows aroundthe inside surface of shell 11. in starting operation the oil spray isignited by spark plug 61 Larger droplets of the oil spray which are notimmediately vaporized or burned are deposited on the wall of shell 11,the skirt 50 and, to some extent, also on the undersides of plates 41.The immediate combustion of the finer droplets greatly i icreases thevolume of gas and the velocity of circular flow, pioducing a strongscrubbing action on any droplets adhering to such surfaces causing allthe droplets to vaporize and burn.

This swelling and accelerating vortex of burning g ises can only escapeby moving downward and toward thr center under the lower edge of skirt50 and around cone 51 and thence upward within skirt 50 and downwardthrough the cone in a tight spiral as shown. This produces a foldedvortex in secondary combustion chamber B. At the upper end of cone 51the burning gases mix with the cooler flows of air from passageways 37and 38 which are introduced into the upper end of skirt 50 from plenumchamber 39. This increased supply of oxygen completes combustion of allthe fuel in an expanding downward moving vortex diverging into tertiarycombustion chamber C.

Y I Beginning a short distance below diaphragm 53 the wall 11 in layersextending from shell 11 inward to a central refractory core 7 2. Theturns of the coils are spaced radially in each layer and are staggeredin vertical direction to intercept all downward radiation from secondarycombustion chamber B and provide tortuous passageways for the flow ofhot combustion gases between the tubes as shown.

Below vapor generating sections 70 and 71 is a liquid preheater section73 which extends down to a steel wire support rack 75. Refractory core72 merely fills the open center of these coils so that there will be nofree path for radiation from tertiary combustion chamber C to impinge onbottom plate 20 and no free path for the passage of combustion gaseswithout wiping the tubes in tube sections 70, 71 and 73. The combustiongas is discharged through support rack 75 and outlet 76.

holes in shell 11 as shown in FIG. 5, thereby allowing free expansionand contraction of the parts in heating and cooling. The whole stack ofcoils is confined 'by an upper ring secured in shell 11 by means ofscrews 81. The tubes in sections 70, 71 and 73 are maintained spacedapart vertically and horizontally as shown by radial spacer strips 77having notches to seat the tubes.

This is a single pass system wherein the liquid is introduced into lowertube section 73 through an inlet connection 85, the liquid flow thenpassing through tube sections 71 and 70 where the liquid is vaporizedand the vapor then passing through tube section 65, where the vapor issuperheated, to outlet 86. The liquid may be water containing a suitablevolatile antifreeze solution such as alcohol, it may be a mixture ofwater and a manufactured chemical, or it may be entirely a manufacturedchemical composition.

The present construction provides an appropriate environment for theefficient and clean combustion of fuel. There are no tubes in theprimary or secondary combustion chambers presenting relatively coolsurfaces upon which partially burned fuel may quench and condense givingrise to unburned hydrocarbons, aldehydes and other noxious compounds inthe exhaust. On the other hand, the combustion temperatures aredeliberately kept below 2800 F. to prevent the highly objectionableoxides of nitrogen from being generated in excessive amounts. The intakeof air directly into the secondary combustion chamber insures completeoxidation of all the fuel, substantially eliminating carbon monoxide.The tertiary or post combustion chamber C provides for completion ofcombustion so that flames do not impinge on the banks of tube surfacesbelow chamber C. These factors reduce any harmful exhaust emission to arelatively low level.

The device will operate satisfactorily in any position. it is notnecessary for it to be mounted in vertical position as shown in FIG. 1.Although the vapor generator is particularly adapted for automotive use,it is not limited to any specific field of use.

Having now described my invention and in what manner the same may beused, what 1 claim as new and desire to protect by Letters Patent is:

1. A vapor generator comprising concentric inner and outer shells, anannular primary combustion chamber in one end of said inner shell, asecondary combustion chamber in the center of said primary combustionchamber, concentric cylindrical heat sleeves surrounding said primarycombustion chamber between said inner and outer shells formingconcentric annular passageways between said shells, means forintroducing air in circular flow between said shells at their oppositeend producing spiral flows of air between said sleeves, meansintroducing said spiral flow from the innermost annular passageway intosaid primary combustion chamber, means introducing said spiral flow fromthe outermost annular passageway into said secondary combustion chamber,tubes for liquid in the opposite end of said inner shell, and an exhaustoutlet in the opposite end of said shells for combustion gases.

2. A vapor generator as defined in claim i, said means in troducing saidspiral flows of air into said combustion chambers comprising an airregister extending across said one end of said inner shell in spacedrelation to an endwall on said outer shell and inturned ends on saidheat sleeves extending between said air register and said end wall.

Support rack 75 comprises crossed wires extending through 3. A vaporgenerator as defined in claim 2 including an annular diaphragm in saidinner shell spaced from said air register, said primary combustionchamber extending between said air register and said diaphragm, saidsecondary combustion chamber. being contained within a circular skirt onsaid air register and a circular wall around the inner edge of saiddiaphragm extending into said skirt.

4. A vapor generator as defined in claim 2, said air register beingarranged to intercept heat radiation toward said one end of said shellsand said liquid tubes being arranged to intercept heat radiation towardsaid opposite end of said shells.

5. A vapor generator comprising concentric inner and outer cylindricalshells, end walls on said outer shell, an air register on one end ofsaid inner shell forming a plenum chamber between said air register andone end wall of said outer shell, an exhaust'outlet in the opposite endwall of said outer shell, means for introducing air in circular flowbetween said shells adjacent said opposite end, a diaphragm across saidinner shell forming a primary combustion chamber between said diaphragmand said air register, a secondary combustion chamber within saidprimary combustion chamber, and a tertiary or post combustion chamber onthe opposite side of said diaphragm, concentric cylindrical heat sleevessurrounding 7 said primary combustion chamber between said inner andouter shells forming concentric annular passageways for conveying saidcircular flow of air to said plenum chamber, multilayered slopingpassageways in said air register arranged to direct air from said plenumchamber into said primary combustion chamber in a circular vortex flow,a tangential fuel spray nozzle in said primary combustion chamber, saidair register being arranged to intercept heat radiation directed towardsaid one end wall, a central opening in said diaphragm communicatingwith said secondary and tertiary combustion chambers, a superheat tubesection in said tertiary combustion chamber, and vaporizing and liquidpreheater tube sections between said superheat tube section and saidopposite end wall of said outer shell, the tubes in said vaporizing andpreheater tube sections being spaced apart to pass combustion gases tosaid exhaust outlet and arranged to intercept heat radiation from saidsecondary and tertiary combustion chambers directed toward said oppositeend wall.

6. A vapor generator as defined in claim 5, said air register comprisinga plurality of inclined, overlapping, spaced apart sector-shaped plates.

7. A vapor generator as defined in claim 5, said heat sleeves havinginturned ends extending into said plenum chamber and overhanging saidair register.

8. A vapor generator as defined in claim 5 including a circalar skirt onsaid air register forming an inner wall in said primary combustionchamber and a circular wall around said opening in said diaphragmextending into said skirt.

9. A vapor generator as defined in claim 5 including resilient spacersbetween said inner and outer shells and resilient spacers between saidshells and said heat sleeves.

10. A vapor generator as defined in claim 5 including notched radiallyextending spacer strips holding said tubes in said vaporizing andpreheater tube sections spaced apart in radial and axial directionsrelative to said shells.

11. A single pass vapor generator comprising a circular tube bundlehaving a hot and cool end, an inner cylindrical shell closelysurrounding saidbundle and having corresponding hot and cool ends, saidhot end of said shell extending beyond said tube bundle to form acombustion chamber, an air register in said hot end of said shellforming one end of said combustion chamber, said air register comprisinga multiplicity of sloping passages directed to give a swirl or vortexeffect to combustion air pressured into said combustion chamber,coaxially spaced baffles within said combustion chamber, an outer shellcoaxial to said inner shell spaced outwardly therefrom and including asolid dome end portion spaced away from said air register, a pluralityof coaxial sleeves spaced between said inner and outer shells located atthe hot ends thereof and extending inwardly on their hot end extremityinto the spacebetween said air register and said dome, means forpressuring combustion air into the space between the inner and outershells near their cool ends, a fuel spray means directed tangentiallyinto a portion of the combustion chamber in a direction to correspond tothe rotation of the vortex of combustion air, and a gas outlet connectedto the cool end of the shells, to provide an integrated vapor generatingunit in which the combustion air is heated prior to combustion forgreater efficiency, said air fonning heat barrier to insulate saidcombustion chamber and in which the air entering the combustion chamberis divided and segregated according to temperature and these gradationsof hot air are introduced into the combustion area selectively toenhance combustion efficiency, and wherein a vortex flow of combustiongases is formed to provide an extended path for said combustion gasesprior to their being exposed to the tube bundle.

1. A vapor generator comprising concentric inner and outer shells, anannular primary combustion chamber in one end of said inner shell, asecondary combustion chamber in the center of said primary combustionchamber, concentric cylindrical heat sleeves surrounding said primarycombustion chamber between said inner and outer shells formingconcentric annular passageways between said shells, means forintroducing air in circular flow between said shells at their oppositeend producing spiral flows of air between said sleeves, meansintroducing said spiral flow from the innermost annular passageway intosaid primary combustion chamber, means introducing said spiral flow fromthe outermost annular passageway into said secondary combustion chamber,tubes for liquid in the opposite end of said inner shell, and an exhaustoutlet in the opposite end of said shells for combustion gases.
 2. Avapor generator as defined in claim 1, said means introducing saidspiral flows of air into said combustion chambers comprising an airregister extending across said one end of said inner shell in spacedrelation to an end wall on said outer shell and inturned ends on saidheat sleeves extending between said air register and said end wall.
 3. Avapor generator as defined in claim 2 including an annular diaphragm insaid inner shell spaced from said air register, said primary combustionchamber extending between said air register and said diaphragm, saidsecondary combustion chamber being contained within a circular skirt onsaid air register and a circular wall around the inner edge of saiddiaphragm extending into said skirt.
 4. A vapor generator as defined inclaim 2, said air register being arranged to intercept heat radiationtoward said one end of said shells and said liquid tubes being arrangedto intercept heat radiation toward said opposite end of said shells. 5.A vapor generator comprising concentric inner and outer cylindricalshells, end walls on said outer shell, an air register on one end ofsaid inner shell forming a plenum chamber between said air register andone end wall of said outer shell, an exhaust outlet in the opposite endwall of said outer shell, means for introducing air in circular flowbetween said shells adjacent said opposite end, a diaphragm across saidinner shell forming a primary combustion chamber between said diaphragmand said air register, a secondary combustion chamber within saidprimary combustion chamber, and a tertiary or post combustion chamber onthe opposite side of said diaphragm, concentric cylindrical heat sleevessurrounding said primary combustion chamber between said inner and outershells forming concentric annular passageways for conveying saidcircular flow of air to said plenum chamber, multilayered slopingpassageways in said air register arranged to direct air from said plenumchamber into said primary combustion chamber in a circular vortex flow,a tangential fuel spray nozzle in said primary combustion chamber, saidair register being arranged to intercept heat radiation directed towardsaid one end wall, a central opening in said diaphragm communicatingwith said secondary and tertiary combustion chambers, a superheat tubesection in said tertiary combustion chamber, and vaporizing and liquidpreheater tube sections between said superheat tube section and saidopposite end wall of said outer shell, the tubes in said vaporizing andpreheater tube sections being spaced apart to pass combustion gases tosaid exhaust outlet and arranged to intercept heat radiation from saidsecondary anD tertiary combustion chambers directed toward said oppositeend wall.
 6. A vapor generator as defined in claim 5, said air registercomprising a plurality of inclined, overlapping, spaced apartsector-shaped plates.
 7. A vapor generator as defined in claim 5, saidheat sleeves having inturned ends extending into said plenum chamber andoverhanging said air register.
 8. A vapor generator as defined in claim5 including a circular skirt on said air register forming an inner wallin said primary combustion chamber and a circular wall around saidopening in said diaphragm extending into said skirt.
 9. A vaporgenerator as defined in claim 5 including resilient spacers between saidinner and outer shells and resilient spacers between said shells andsaid heat sleeves.
 10. A vapor generator as defined in claim 5 includingnotched radially extending spacer strips holding said tubes in saidvaporizing and preheater tube sections spaced apart in radial and axialdirections relative to said shells.
 11. A single pass vapor generatorcomprising a circular tube bundle having a hot and cool end, an innercylindrical shell closely surrounding said bundle and havingcorresponding hot and cool ends, said hot end of said shell extendingbeyond said tube bundle to form a combustion chamber, an air register insaid hot end of said shell forming one end of said combustion chamber,said air register comprising a multiplicity of sloping passages directedto give a swirl or vortex effect to combustion air pressured into saidcombustion chamber, coaxially spaced baffles within said combustionchamber, an outer shell coaxial to said inner shell spaced outwardlytherefrom and including a solid dome end portion spaced away from saidair register, a plurality of coaxial sleeves spaced between said innerand outer shells located at the hot ends thereof and extending inwardlyon their hot end extremity into the space between said air register andsaid dome, means for pressuring combustion air into the space betweenthe inner and outer shells near their cool ends, a fuel spray meansdirected tangentially into a portion of the combustion chamber in adirection to correspond to the rotation of the vortex of combustion air,and a gas outlet connected to the cool end of the shells, to provide anintegrated vapor generating unit in which the combustion air is heatedprior to combustion for greater efficiency, said air forming heatbarrier to insulate said combustion chamber and in which the airentering the combustion chamber is divided and segregated according totemperature and these gradations of hot air are introduced into thecombustion area selectively to enhance combustion efficiency, andwherein a vortex flow of combustion gases is formed to provide anextended path for said combustion gases prior to their being exposed tothe tube bundle.